Cut-off valve for drill stems



May y16, 1933.

E. C. JOHNSTON ET AL CUT-OFF VALVE FOR DRILL STEMS Filed sept. 4, 1951F' EDGAR CJOHNSTON E 3 JOHNFFWLER JR.

INvENToRa @im f5` @uk ATTORNEYS.

Patented May 16, 1933 UNITED STATES PATENT OFFICE EDGAR C. JOHNSTON ANDJOHN F. FOWLER, JR., OF LONGVIEW, TEXAS cU'r-orr VALVE For. :DRILLstraus Application led September 4, 1931. Serial No. 561,138.

.adjacent the cutting face of the bit. This mud then carries awa thecuttings from the bit and flows upwar y around the outside of the drillstem. Another purpose of this circulation is to mud-in the walls o theformation and prevent caving, and it is usual to make this mud quiteheavy so that the walls of the well bore will be maintained.

VThe present invention contemplates the use of a device which willadvise the 'driller almost instantly when the drill bit deviates fromthe vertical, and this device is of the type which will cut off thecirculation of the Huid passing through the drill stemwhen the drill bitdeviates from the vertical.

The circulation of mud is accomplished by means of slush pumps, and whenthe circulation is stopped for some reason, these' pumps will stallbecause the pressure required to maintain the circulation isv greaterthan the capacity of the pump. The driller realizes instantly when thepumps stall that circulation has been stopped, and the present inventionuses a device to cut oil the circulation when the drill bit deviatesfrom the ver tical so that the driller is advised by the stalling of hispumps that his bit has deviated from the vertical more than apredetermined angle. n Y l One of the objects of the invention is toprovide a means and method of instantly advising the driller when thedrill bit deviates from the vertical.

Another object of the invention is to provide a means of detecting drillbit deviation by controlling the circulation of flushing fluid in thewell in such a manner that the circulation will be restricted or cutoli' when the bit deviates` beyond a predetermined angle with respect tothe vertical.

, A still further object of the invention is to provide a coupling fordrill stems containing a gravity actuated valve, which is arranged tocutJ 0E the iiow of fluid through the tool joint when the tool oint isinclined with respectto the vertical.

It is also an object of the invention to provide an oscilllatable memberin combination with a tool joint or drill collar so that the flow offluid through the drill bit will be restricted when thebit assumes aninclination with respect to the vertical.

Other and further objects of the invention will be readily apparent tothose skilled in the art, when the following description is consideredin connection with the accompanying drawing, wherein :l

Figure l is a central vertical Section through the tool joint or drillstem cable, which has been equipped with the invention.

Figure 2 is a section taken on the line 2-2 of Figure l, and looking inthe direction of the arrows.

Figure 3 is a broken sectional View showing certain parts o-theinvention in elevation, and certain parts in section, and illustratingthe invention as applied to a drill bit positionedv in the well bore.

The drill stem lused in drilling the .well is indicated generally at 2,and extends t0 the surface of the eartli. This drill stern is connectedby tool joints or couplings, and carries the drill bit 4 on its lowerend. In some instances a tool joint or drill collar is used to couplethe drill stem and bit together, and it is contemplated that thisinvention may be incorporated in a tool joint or drill collar usedadjacent the top of the drill bit. Such a drill collar or tool joint isindicated in Figure 3 at 5, and shows the relationship of the device tothe remaining parts of the drilling equipment. It is understood that thedrilling of the well is accomplished by the rotation of the stem 2,

drill collar 5 is shown as being formed to receive an upper bushing 7and a lower bushing 8. These bushings are preferably threaded in thetool joint 5 from opposite directions and are retained in position bythe threads 9 formed on the tool joints and the bushings. The bushings 7and 8 are arranged to abut with each other at 10, and in this manner,serve as lock nuts for each other to insure that they will remain inposition. Depressions 11 are provided in each of the bushings toYreceive a Spanner wrench for inserting or removing the bushing.

The upper bushing 7 is provided wlth a passage 13, which is in turnfitted with a replaceable sleeve 14. It is through this passage that theflow of fluid to the drill bit must pass. Positioned between the upperbushing 7 and the lower bushing 8 is a ball valve 15. This valve has apassage 16 therethrough, which is arranged to normally serve as acontinuance of the passage through the upper bushing 7. This ball valve15 is mounted on antifriction bearings 17, which are positioned ingrooves or openings 18 in the bushings l7 and 8. These openings 18 arepreferably annular in form so that a series of ball bearings or rollerbearings ma be positioned ineach groove so that the all valve 15 willmove with a minimum of friction. In order to maintain the bearings inoperative condition, a acking ring 20 is provided in each ofathe ushings7 and 8 adjacent the center thereof, and arranged to form a seal aboutthe passage. and to contact the ball valve. A similar packing ring 20 isprovided in the lower bushing 8. In assembling the device, one of thebushings-may be placed in position and the ball valve seated therein.The device can then be inverted and the remaining bushing placed inlocking position so that the ball valve 15 maybe maintained in positionsuch as shown in Figure 1. The lower bushing 8 is provided with acut-away area (21, which is arranged to permit passage of the weightedportion 22 of the ball valve. This weight is connected by means of thestem 23 to the ball valve, and is provided in order that the valve willremain in the position shown in Figure 1, with the passages 16 and 13Cinalignment when the tool joint is in a vertical position. However, whenthe tool joint is inclined the weight 22 will-seek a vertical positiondue to the force of gravity and will tend to tilt theball 15 so-that thepassage 16 is no longer in alignment with the passage 13. In this manner`the flow of Huid through the drill stem is either-restricted orcompletely cut olf, depending upon the degree of the inclination of thetool joint with respect to Ithe vertical. The cut-away shoulder in thebushing 8 allows of a tilting movement of l the ball valve 15 and theweight 22 so that it may assume a maximum inclination with respect tothe tool joint, such as shown in,

the dotted line position in Figure 1.

It is intended that the ball valve 15, or other valve member used inpractising the invention, may be mounted in any manner other than thatshown in Figure 1, so lon as'the essence. of the invention is practiseand this consists of restricting the flow` of fluid through to the drillbit directly in proportion to the degree of inclination of the drillbit.

When the drill bit is provided with a device such as herein described,it seems readily apparent that so long as the bit is penetrating theformation in a'vertical direction, such as well `bore 30 of Figure 3,the valve 15 will remain in open position due to the force of gravitybecause of the Weight 5.

cHowever, when the drill bit strikes some obstruction or is otherwisecaused to deviate from vthe vertical its deviation will be quicklyapparent to the driller because the force of gravity will cause theweight to maintain the passage 16 through the valve in a verticalposition, and if the inclination is of a suiiicient amount to cause thepassage 16 toy move out of alignment with the passage 13 it is thenapparent that the ilow of fluid through vthe passage 13 will berestricted. Its restriction will increase the pressure required to causecirculation and the driller 4will instantly notice that the slush pumpis laboring to maintain the circulation, and when he knowsthat thisinvention/has been Aincorporated in the tool joint, he is then awarethat his drill bit has deviated from the vertical to a sufficient anglethat the circulation is being restricted. -He can then withdraw thedrill bit and plug back the short distance 31 of the hole which hasdeviated from the vertical and then continue his drilling irra verticaldirection.

With some types of modern equipment high speed rotation of the drill bitis possible. When this occurs the valve may be constructed withoutanti-friction bearlngs. It is also ossible that when high speed rotationof t e drill bit occurs that the weight 22 when once moved oif center byinclination of the bit will then, due to centrifugal force, instantlymove over to the maximum position such as shown in the dotted lineposition of Fig. 1.

Thus, in ractising the invention, the driller is advised when his bithas inclined from the vertical but a few degrees, and can instantlyremedy the diiiiculty; whereas, with the present practise the bitdeviates, and', in many instances, several hundred feet of hole aredrilled before the operator is advised that his well is crooked. It isthen necessary to plug back this several hundred feet by filling thehole with cement, and he can then attempt to drill a vertical hole.

The 00st of this plugging back operation is 130 quite expensive anddelays the drilling of the Well. When the present invention isincorporated in the drill collar or tool joint ad]a cent the bit, theoperator will be instantly advised of any deviation, and can then makehis correction before any considerable crookedhole has been drilled.

It is contemplated that in the future development of the invention thatvarious alterations and modifications may be resorted to, and that thestructure shown herein and described is for purposes of illustrationonly, as the invention contemplates broadly the idea of indicating tothe operator the deviation of his bit by .restricting or cutting oil theflow of fluid through the drill stem.

What we claim is: I

1. In combination with a drill stem coupling, a valve seat having apassage therethrough, a valve for said seat having a passagetherethrough which is adapted to be normally in alignment with saidvalve seat assage, a depending weight on said valve aving a passagetherethrough, said three passages being adapted for alignment when saidcoupling is disposed in a vertical position, and anti-friction bearingssupporting said valve whereby said weight will cause movement of saidvalve and closing of said passae when said coupling is inclined.

2. gravity operated cut-olli` valve for drill stems to close off thepassage of fluid when said stem is inclined beyond a predetermineddegree, includingr a seat construction, a ball valve disposed in saidseat for swiveling movement, a weight connected to said ball valve anddepending therefrom, a passage throughsaid seat and a passage throughsaid ball and weight which passa es are adapted to be aligned but whichwillgbe moved out of alignment by swinging of said weight to swivel saidvalve.

- 3. A gravity operated cut-oil' valve forv drill stems to close off thepassage of fluid when said stem is inclined beyond a predetermineddegree, including a seat construction, a ball valve disposed in saidseat for swiveling movement, a weight connected to said ball valve anddepending therefrom, a passage through said seat and a passage throu hsaid ball and weight which passages are adapted to be -aligned but whichwill be moved out of alignment by swinging of said weight to swivel saidvalve, and a sealing ring between said valve and seat about saidpassage.

In testimony whereof, we hereunto ax our signatures this 22nd day ofAugust,

EDGAR C. JOHNSTON.

JOHN F. FOWLER, JR.

